Digital Mixer Buyer's Guide

Introduction

The professional audio mixer (sometimes referred to as a console, board, desk or combination thereof) is the brain of the sound reinforcement system, as well as the recording studio.

A wide variety of sound sources can be connected to the mixer. This includes wired and wireless microphones, instruments, playback media (such as video audio, CD and cassette players, computer audio, mp3 players, USB and SD cards, etc.) and more. The mixer will then process and balance the audio inputs and route the mixed audio to multiple destinations such as monitor mixes, front of house loudspeakers, matrix outputs, or directly to recording (DAW) software.

The following guide assumes you possess a thorough understanding of mixer functions. If so, you will be able to operate either an analog or digital console, effectively.

The question is, analog or digital? Many users are now turning to digital mixers. Whether analog or digital, certain aspects of mixers are universal. Inputs, channel strips, on-board effects, bussing (also referred to as routing), and outputs are common traits.

Analog vs. Digital

Many musicians have been switching over to digital mixers due to them being more flexible than their analog counterparts. Some mixers are a hybrid of analog and digital where the FX architecture and ability to record are digital, but all other aspects of the signal chain remain analog.

The main difference between digital and analog mixing boards is how audio is processed. Our instruments and voices are in analog form but once they enter the console, they will either remain as such or be processed and converted to digital. Some of you may be familiar with this concept due to the popularity of audio interfaces. The audio interface takes analog signals and turns them into digital so that they can be recorded by a computer. Inside the audio interface this job is done by a component known as a converter. The analog to digital converter receives your guitar or vocals and converts them to digital information which is then transferred to the computer via USB, Firewire, or Thunderbolt. Similarly yet reverse, there is a digital to analog converter which takes the digital output from the computer, back through the same protocol (USB, Firewire, or Thunderbolt) into the audio interface, converts it to analog, and sends it to the analog outputs which are usually 1/4”, XLR, or RCA.

Digital mixers have been around since the late 80s but due to increased processing power and reduction of cost, they are now more popular than ever. This is due to their convenience, expandability, and resistance to noise.

Advantages of Digital Mixers

Before getting into the main features of digital mixers, let’s explore a few of the reasons why somebody might choose analog. Traditionally, analog mixers are a more economical choice (however, digital mixers are a far better value due to the onboard signal processing, which is absent in analog mixers). In addition, they are simpler in terms of features, which provide beginners with an easier understanding of how everything works. Signal flow is laid out in a logical manner; what you see is what you get and each channel is identical.

In some digital mixers, routing audio is so flexible that it’s not always as easy to guess where the controls are, as they might need to be accessed from menus within the mixer’s software interface. Many of the digital mixers sold by AMS have a fixed 1:1 signal flow but the output routing can be varied. This could lead to confusion if there are multiple operators on one mixer, and for this reason, analog mixers are sometimes preferred in schools and public meeting halls.

Better Sound Quality
In every sound system, noise is lurking. Long cable runs introduce it, microphones pick it up; it’s unavoidable whether the mixer is analog or digital. When analog signals are affected by noise, the change is irreversible which could result in distorted output. Since digital audio is just zeroes and ones, underlying signals are less affected by noise. Digital excels in the ability to resist noise and signal degradation.

Recallable Settings
One of the main advantages of most digital mixers is their ability to be pre-programmed. On-board memory allows the user to set the mixer up, and then save the settings for future use. This is a huge advantage to venues and banquet halls where the configuration may change depending on the type of event. Recalling basic parameters can be a great starting point and time-saver. Best of all, if somebody accidentally changes something, it’s easy to return to the previous state.

Processing Power
Audio remains in the analog domain at the inputs and outputs of the mixer. The digital conversion occurs in between these stages, and this is where the magic happens. Digital mixers have the ability to process audio in real-time with useful tools such as delay, reverb, equalization, compression, limiting, gating, pitch and modulation effects, and de-essing on every input channel (and often on every output channel as well). This is due to what is known as digital signal processing (DSP). While some analog mixers have DSP effects, they are generally limited in terms of capability. Also, digital effects in an analog mixer will increase the overall cost. In this respect, digital mixers offer superior economy. Software aids in additional processing and it is very flexible based on application. They also negate the need for external equipment such as compressors since everything is possible from within the console.

Digital snakes are boxes full of inputs that can be placed on stage, which then carry all the signals in digital format (via Ethernet) to the mixer, which might be in the middle or back of the house. Having all the audio through one Ethernet cable negates the need for heavy and expensive, traditional analog snakes.

Digital snakes are usually specific to the manufacturer so make sure you research the particular mixer you’re interested in to see if they offer this accessory. A great feature of being digital is in the ability to control the inputs remotely, such as applying microphone gain to specific inputs. Not to mention, superior audio quality.

Function Switching Controls
On analog mixers, each button serves a specific purpose. Since digital mixers are built on software, each button can change function based on the application. This makes it possible to pack lots of features into a board that might be the same size as its analog counterpart. This holds true for channels as well. A digital mixer can have 64 channels with only 16 physical channel strips. This lends to a significantly smaller footprint.

Flexibility
In the analog realm, inputs are hard-wired and not changeable. On the contrary, digital mixer channels can be routed in whichever way the engineer desires. In addition, each channel can employ multiple effects, each with their own settings. Combine this with the ability to recall (such as remembering the equalizer settings for a specific singer’s microphone), and you can see why digital mixers are more versatile.

Digital Mixer Effects

Digital mixers are software based and due to the advanced processing capabilities, they excel at effects. Most units have multiple dedicated FX engines and all of the available processors can usually be used in any combination. This allows you to choose the effects needed on each channel, as well as the order in which they are routed. It’s really only limited by the amount of FX buses that are built into the framework of the mixer. Also, thanks to advanced on-screen controls (via touch screens), you can tweak each channel’s setting exactly the way you like it.

Analog boards that have digital effect processors tend to be limited in terms of available parameters. In the digital realm, each effect has several different specifications which can be tweaked. Best of all, being that everything is digital, effects can be saved and instantly recalled.

Another thing to consider is the sheer amount of effects digital mixers have onboard. A virtual equipment warehouse is present for you to choose the exact type of reverb or delay for the job at hand. Combining them and saving allows you to have your own arsenal of effect chains at your disposal.

Any input can be sent to any effect. Once the processor has done its job and created the wet sound, this is combined with the dry, un-affected signal which is then sent to the mixer’s outputs.

Typically each input channel will have multiple post-fader effect sends available. The effect processors will usually have returns to the mains and aux outputs. This can be useful if you want to apply a certain effect to specific monitors on stage. For example, one singer may perform better when hearing their voice with extra reverb. Many units will also have a Tap Tempo function to sync effects to the BPM of the song.

Touch Screens / iOS Control

A common misconception is that digital mixers are more difficult to use. While the initial learning curve might seem intimidating, once you get familiar with the user interface you will find that digital mixers are far more intuitive and capable of tasks that are similar to those found in DAW software. This is due to the large, built-in touch screens, and compatible apps that allow you to control the unit via a tablet or mobile device.

As intimated early, everything you see on the surface of a digital console is not indicative of the power beneath the hood. Digging into the menus of the touch screen will provide you with a map for further control. Once in the mode of choice, many times factory presets will help to get you started, or you can begin from scratch and create your own. As you change the mode, the screen will instantly change to provide a host of parameters to alter to your liking.

Similar to the touch screen, many mixers have apps available to control the most sought after functions using an iPad, iPhone, or sometimes Android device. This can be useful if the engineer is away from the board in another part of the room and wants to adjust the levels of a particular channel. Common parameters such as auxiliary mixes, pans, effects return levels, and record and playback functions are commonly available.

Once the app is downloaded to the device, it can usually connect to the mixer via WiFi.

WiFi

Many contemporary digital mixers have a built-in, or optional (via a card, dongle, or external router) WiFi feature which allows them to connect to mobile devices for remote user control. There is usually a mode within the mixer to turn on the WiFi access point. It will then become discoverable so that you can connect with your computer, phone or tablet. The connecting device will need to have the mixer’s proprietary software installed prior to connecting. These can easily be found by checking the support section of the manufacturer.

Recording

Computer Recording
Recording ability is a common function of today’s digital mixers. Most of them have a digital computer connection such as USB or Firewire that will not only allow for recording, but also essentially turn the mixer into an audio and MIDI interface. For this reason, digital consoles not only excel for live sound, but also recording studios, and sometimes as a hybrid of both. Imagine setting up your band in a live venue with a multi-miked drum kit and then having the ability to record the mix the audience hears. This is now all possible.

Whereas some mixers will only record a two track mix (left & right channel) of the master output, most will allow for capturing each individual channel as separate tracks. This is very useful for creating alternate mixes after the fact, or further processing with D.A.W. software. Some mixers even come with D.A.W. software, essentially making them an almost complete recording solution in addition to a live sound controller in one.

Using digital mixers as an audio interface has advantages. Some units will allow you to use the mixers knobs and faders to control the graphic user interface of the computer recording software (done via MIDI). In addition, often the on-board effects of the mixing console can be used to bus audio to and from the computer. For example, you can take a vocal track from your D.A.W. software, send a portion of it into the mixer for processing, and back into the software. Conversely, certain digital consoles allow for the reverse, meaning you can use a plug-in effect from your DAW as an insert effect on your digital mixer.

Hard Disk Recording
Several digital mixers allow for on-board recording without a computer. They may also offer computer recording as an option, but for situations in which you don’t want to bring a computer to the gig, hard disk recording is very convenient. Similar to computer recording, the hard disk (usually in the form of an external USB drive or stick) can either record a two-track stereo mix, or each individual channel separately. The files are normally saved as studio-quality WAV files which can then later be imported to your D.A.W. of choice for further mixing and mastering.

In addition to recording stereo or multi-track files, these digital consoles will also allow for playback should you want to hear your mix after the recording is complete.

Control / Motorized Faders

One of the huge advantages digital mixers have over analog is their ability to control D.A.W. software. This is done via the MIDI protocol (Musical Instrument Digital Interface) which is transmitted through the computer connection (USB, Firewire, etc.).

Another cool feature that some digital mixers have is the addition of motorized faders. These are great for recording sessions in which engineers want to record their mix automation. As the session plays back, the faders move automatically based on how the movement was recorded.

Rack-Mountable Mixers

Due to the added functionality provided by devices that can control digital mixers (such as iPads), some people prefer rack-mountable mixers. They pack the same power and flexibility as their console-style cousins, but are more compact for use in an equipment rack or on a desktop. To get to a smaller form factor, many of the physical channel strip controls and faders are removed. This frees you to mix from your tablet, or by using the touchscreen that many units still employ.

Rack-mount mixers are a failsafe solution for schools, hotels, corporate events, and live music bars. These pro mixing solutions not only have a tiny footprint, but are also usually compatible with digital snakes from the manufacturer.

Accessories

When purchasing your digital mixer, make sure you have all the accessories you might need.

Road cases: Protect your investment from the rigors of the road with a hard case that is designed to fit either the exact model you have.

Digital snake: A digital snake will allow you to have all of your inputs from the stage, sent back to the mixer in one cable. They also have the ability to be controlled remotely. Inquire with the manufacturer to get the correct compatible snake.

Microphones: You can never have too many microphones. Each one is like a unique paint brush that will impart sonic character.

Expansion cards: Check the manufacturer’s site to find out about available expansion for your console. Many have proprietary cards that can add advanced digital I/O.

Storage devices: If your digital mixer can record to a hard disk, figure out what type of media is needed. Some have internal hard disks but most can record to USB drives or memory cards.

Headphones: It’s always a good idea to have a pair of quality headphones when mixing. In a loud venue your mix is competing with the sound of the crowd. Headphones provide an additional point of reference.

Mixer stands: Where is your mixer going to live? A proper mixer stand is essential to keep your console safe. Do not try and use a keyboard stand as they are not properly weighted to hold a digital mixer.

Audio Cables: Make sure you have all your cables before the gig. This includes cables to bring your audio from the master outputs to the house’s amplifier or powered speakers.

Summary

As you’ve read, most digital mixers are way more flexible than analog mixers. Many people feel they have a lower cost over time due to not having to buy anything else. Having an extensive library of effects on hand gives you an enormous amount of power to sculpt your sound. The major manufacturers of live sound equipment build these units to be reliable which means low maintenance. Since they are software-based, firmware can be updated to fix bugs or add new features. Combine all this with the ability to save and recall your settings, and it’s understandable while they have become so popular both in the live setting, and studio.

About the Author - Headsnack

Headsnack has specialized in creating training materials for some of the biggest names in music gear retail, for over 12 years. His Training Snacks brand has produced several pro audio category and product training segments which can be found on YouTube and in written form on AmericanMusical.com.

As a musician, Headsnack is a positive-minded producer, performer, and lyricist who specializes in electronic beat-making and writing hilarious songs that mock humanity. His music, which has been described by fans and reviewers as everything from “conscious hiphop” to “next-level pop”, has been licensed to several artists, labels and films including Public Enemy, Sky Mall, and the Independent Film Channel. His viral-style YouTube videos have garnered over 60,000 views and he has also DJ’d for various clubs and parties for over 15 years.

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